Imperial Sentinels were armored-and-cloaked warriors assigned to serve EmperorPalpatine's Dark Side Adepts. Cloned in hidden facilities on the secret Imperial throne world of Byss, these mute giants were mutated by Dark Side Adepts and injected with chemicals that suppressed their higher brain functions, causing them to become completely subservient. For the duration of their natural existence, Sentinels were slaves to their assigned Adept and carried out their master's bidding without question. They accompanied the Adepts on missions off-world, typically acting as bodyguards.
Mainly remaining on Byss to guard the Emperor's Citadel, Sentinels had only been seen a handful of times in the short history of the Empire. This led to a great deal of speculation among the upper echelons of the Empire as to what exactly these armored behemoths were. In 10 ABYLuke Skywalker, after defecting to the Empire, was known to have bred at least two of his own Sentinels. After a bold attempt to rescue Skywalker from Byss, PrincessLeia Organa Solo—Skywalker's sister and prominent New Republic Council member—and Han Solo—Leia's husband and pilot of the Millennium Falcon—were escorted by Skywalker's Sentinels to Palpatine's clone laboratories on Byss. There they confronted both Skywalker and Palpatine himself. One year later, most of the Sentinels and their cloning facilities were obliterated with the destruction of Byss and the final death of Palpatine.
The origins of the Imperial Sentinels remained a mystery for most in even the highest levels of the Empire. Even the Imperial Sovereign Protectors, an elite cadre of Royal Guardsmen trained in the dark side of the Force, had no idea, nor interest, in how the Sentinels came to be.[2] The Sentinels were in actuality an early experiment of EmperorPalpatine and his inner circle of dark side Force-users to create a race of beings completely subservient to their will.[1] Sentinels were cloned from tissue stock[3] in hidden facilities on the Imperial fortress world of Byss,[1] where chemicals were introduced into their bodies during the gestation period, suppressing higher mental abilities such as speech.[2]
During the growth cycle, Sentinels were mutated by Dark Side Adepts through Sith alchemy as part of their training, during which the Adepts would attempt to form a mental bond with the Sentinels. If the process was successful, the Sentinels would end up as mindless living hulks totally dependent upon the will of the Adepts for purpose or movement. If the process was unsuccessful, the would-be sentries were simply disposed of.[2] First-generation Imperial Sentinels were deemed too dangerous to keep around leading to rumors that they may have been cloned from Force-sensitive individuals. Later generations were much less powerful but far easier to control.[7]
Sentinels functioned primarily as bodyguards for Dark Side Adepts.[2] Whenever Palpatine sent an Adept or ExecutorSedriss on a high-priority mission for the Empire, one or more of these titans would escort them off-world. Few of these creatures existed, however, and when not on-duty with an Adept they would remain on Byss to protect the Emperor's Citadel.[3][2][8] Some Sentinels also guarded the more secure and private areas of the Imperial Palace on Coruscant.[6]
As of 2 BBY, the Sentinels were still in their early stages of development and rarely left Byss. Occasionally, however, Sentinels would be seen briefly in public taking custody of Force-users—often Jedi—while in transit to Imperial Center or other locations.[1] This led to a large amount of speculation and gossip among the Imperial court about the Sentinels and where they came from. Some believed that the Sentinels originated from a captured race of giants while others believed them to be cyborgs or droids.[2][8] Some even speculated that they were formed from a species who once openly rebelled against the Emperor and paid the ultimate price for their disobedience.[3]
The Sentinels would not see widespread use until over a decade later in 10 ABY after the launch of Operation Shadow Hand, the "reborn" Palpatine's military campaigns against the New Republic and its allies to once again take control of the galaxy. Operating out of Byss, Palpatine made use of Imperial Dungeoneers and dungeon ships to ferry and administrate prisoners of war. Sentinels often worked in tandem with Dungeoneers, escorting prisoners such as Luke Skywalker, Jedi Knight and hero of the New Republic, to facilities on Byss. After Skywalker's defection to the Empire, he apprenticed himself to the resurrected Palpatine and bred two of his own Sentinels. PrincessLeia Organa Solo, New Republic councilor and Skywalker's sister, her husband Han Solo, pilot and former New Republic general, and the droid C-3PO later made an attempt to rescue Skywalker from Byss and flew the Millennium Falcon straight into the Emperor's Citadel. Skywalker appeared before Leia and had his two Sentinels escort the Falcon's crew to Palpatine's clone laboratories hidden beneath the surface of Byss. After realizing how far her brother had fallen to the dark side and finding out that Palpatine was still alive, Leia attacked and severed the right hand one of these Sentinels when it restrained Han under Palpatine's orders. This resulted in Leia's capture and the imprisonment of the rest of the Falcon's crew.[4][11]
As Operation Shadow Hand progressed, Sentinels continued to see use as guards in the Emperor's Citadel even after the Battle of Balmorra.[12] In 11 ABY Palpatine's newest flagship, Eclipse II, was boarded by a New Republic strike team led by Lando Calrissian and Kam Solusar. The astromech droidR2-D2 sabotaged Eclipse II's hyperdrive system and sent the Star Dreadnought on a collision course with the planet Byss. Eclipse II exited hyperspace too close to the Galaxy Gun, the Emperor's latest superweapon, and caused the cannon to fire prematurely. The projectile collided with Byss, destroying the planet along with many of the Sentinels stationed there and their cloning facilities.[13]
Gargantuan in size, Imperial Sentinels were easily distinguishable from any of Palpatine's other minions. The sight alone of a Sentinel following in the wake of a Dark Side Adept was enough to strike fear into the hearts of the Emperor's enemies.[3] Sentinels were mute due to the introduction of harmful chemicals into their bodies which also caused them to lose the ability to think for themselves. They were altered through the use of Sith alchemy and completely dependent upon the will of Adepts, only able to do what they were told. It was rumored that Adepts had the ability to view what Sentinels perceived, thus allowing them to maintain complete control of the titans; however this claim was never verified.[2]
The primary choice of weapons for Sentinels were large vibro-axes, though they were also proficient in the use of blasters.[2][3] They also had training in both martial arts[1] and beast-riding. Sentinels donned heavy battle armor[2] under long, reddish-purple cloaks emblazoned with intricate gold patterns at the chest, back and shoulders. They wore large helmets that concealed both the head and neck, leaving only their glowing red eyes visible. No parts of their bodies were left uncovered.[14]
The original design for the Imperial Sentinels could be traced back to old Return of the Jedi concept designs for the Emperor's Royal Guard by Nilo Rodis-Jamero.[16][17] One design depicted a pair of sentries wielding battle-axes similar to those used by the Sentinels in Dark Empire. This sketch was later used to depict a group of bounty hunters known as the Taloron Hunters in The Star Wars Sourcebook.[18] Another design, more closely resembling the Sentinels, was used to create the character Atha Prime, a Clone Master who was to be the antagonist for a new storyline set after Return of the Jedi. Titled The Epic Continues, this storyline was to be adapted into a new toy line as early as 1986 by the toy company Kenner. Several design sketches were drawn including one of Prime, who strongly resembled a Royal Guardsman from the Return of the Jedi concept art. The proposal for the new storyline was, however, rejected by Lucasfilm Ltd. and the toy line was effectively canceled.[16]
―One of the Sentinels' distinctive phrases in the Dark Empire audio drama — Listen (file info)[src]
The Dark Empire audio adaptation was released in 1994, three years after the release of the original comic series. The audio drama was notable for including extra scenes not found in the comics as well as changing much of the comic's dialogue, this ended up creating numerous continuity errors between the audio drama and comic series. For the purposes of this article, the comics as well as most other sources take precedence over the audio drama.[11]
One noticeable continuity error concerning Sentinel speech could be heard throughout the audio drama where several Sentinels were given the ability to speak despite the fact that numerous sources, including the Dark Empire Sourcebook, specifically stated that Sentinels did not possess this ability. In the audio drama, the Sentinels spoke in loud, booming voices and were typically restrained to simple phrases such as "halt droid" and "prisoner secured," with rare instances where they could be heard muttering near-complete sentences. These lines did not appear in the Dark Empire comic series and were exclusive to the audio drama.[11]